Pump.



J. ASTROM.

PUMP. l APPLIUATIQN wenn SEPT. 28.11908.

991,469. Patented May 9,'1911.

lll/[1111x011] JOHN ASTROM, 0F FORT WAYNE, INDIANA.

PUMP. v

Specification of Letters Patent.

Patented May 9, 1911.

Application filed September 28, 1908. Serial No. l55,043.

To all whom it may concern:

Be it known that I, JOHN AsTRoM, a citizen of the United States, andresident of Fort Wayne, in the county of Allen and State of Indiana,have invented certain new and useful Improvements in Pumps; and I dohereby declare that the following is a full, clear, and exactdescription thereof.

My invention has for its object to provide simple, economicalpiston-pumps each having the least possible number of parts so assembledas to permit of its being operated at a much higher speed than ispossible with an ordinary pump, whereby provision is had for reductionof its size for a predetermined capacity, and said invention consists inwhat is herein particularly described with reference to the accompanyingdrawings and pointed out in claims as constituting a piston-pump devoidof suction-valves and having discharge-valves of a free areaapproximately equal to the area of the pump-cylinder, the fluid to bepumped being in direct contact with said cylinder under the leastpossible resistance to flow.

Figure l of the drawings represents a longitudinal central section of myimproved pump, and-*is indicated by line 1 1 in the next in ascendingnumerical order of the several views; Fig. 2, a transverse sectionalview of the pump indicated by lines 2-2 in the next in ascendingnumerical order vof said views, and Fig. 3, a horizontal section of saidpump indicated by lines 3-3 in F ig. l.

Referring by letter to the drawings, o indicates vpump-chambercontaining a pump-cylinder c with which it is preferably integral, thewall o-f the cylinder being centrally provided with open ports Z atsuitable intervals of its circumference. The pumpcylinder is headlessand its ends constitute seats for valves c, and opposite the ends ofsaid cylinder the pump-chamber Z) is provided with openings f covered byheads g bolted to' said chamber. These heads are provided with exteriorstuffing-boxes z, of ordinary construction for the packing for acontinuous piston-rod z' that extends through the pump-chamber andcylinder, the pumppiston y' being fastened by a key 7c on said rod. Thispiston has concave, preferably conical, end surfaces and being carriedon the rod z' it does not tend to wear the pumpcylinder. lThe valves ehave convex faces that match the end surfaces of the piston j,

and thus the clearance between said piston and valves may be reduced inany desirable degree. The valves are provided with hubs e loose on thepiston-rod z', and said valvesy areheld against their seats by springs minterposed between the same and the heads g the pump-chamber is dividedinto a pair of i suction-compartments 1 and a dischargecompartment s,these compartments being outside of and completely surrounding thepump-cylinder.

rlhe wall of the cylinder projects into the suction-compartments and i ithese compartments are united and open below said cylinder. Thedischarge-compartment is intermediate of the suction-compartments abovet-he cylinder, and incloses the ends of said cylinder, its outlet beingan opening t in the pump-casing.

In practice, reciprocating motion is imparted to the rod i and thepiston j therewith, by any suitable means, and when said piston movesfrom the extreme of its stroke in one direction, a vacuum or partialVvacuum is formed between it and the adjacent valve until clearance ofthe cylinder-ports d begins, at which time the fluid in thesuction-compartments r of the pump-chamber b has free access to thecylinder c back of said piston and rapidly fills the space owing to thedifference of pressure in said cylinder and said suction-compartments,the gravity of said fluid or both of these causes. As the pistonproceeds on its stroke, fluid ahead of same is trapped in the cylinderand during the remainder of said stroke this trapped fluid is positivelydisplaced and forced out of said cylinder, the opposing valve beingunseated against spring-resistance to permit escape of said fluid intothe discharge-chamber s having the outlet t aforesaid. The 0perationabove described takes place when the piston is on stroke in eitherdirection, and hence the pump is double-acting. The vacuum or suctionproduced in the pump-cylinder for a time on each stroke of the piston isa resistance denoting an apparent loss of work, but this resistancedecreases with the absolute pressure in the suction-chambers, andtherefore if the pump is used in connection with a condensing apparatusor other source of continuous Huid supply of very low absolute pressurethe loss aforesaid practically disappears. The aforesaid loss is alsogreatly or totally eliminated by the inertia of the fluid entering thecylinder and creating an additional pressure on the piston and valveahead of same, which pres sure, furthermore increased by the speed andconcave shape of said piston, causes said Valve to unseat before theHuid is trapped by said piston, whereby the eiiciency of the pump isenhanced. In other words, the work apparently lost by suction pressureis partially or wholly restored by the inertia of the fluid, whichassimilates same inthe Way of velocity.

I claim:

1. A double-acting piston-pump devoid of suction-valves and comprising achamber partitioned to form a pair of suction-compartments having acommon inlet and a discharge-compartment between thesuctioncompartments, a horizontal cylinder open in its wall to thesuction-compartments of the chamber and having its ends within thedischarge-compartment of the same, spring loaded valves normally closingthe ends of the cylinder, and a piston reciprocative Within saidcylinder to alternately open and close the same with respect to eachsuctioncompartment; the aforesaid valves being alternately unseatedincidental to the movement of the piston.

2. A double-acting piston-pump devoid of suction-valves and comprising achamber divided into a pair of suction-compartments having a commoninlet and a discharge-compartment between the suction-compartments, ahorizontal cylinder partly within said suction-compartments with whichit communicates and which has its ends in said JOHN ASTROM.

Witnesses:

SAML. L. MORRIS, Jol-1N JELLEFF.

- Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

